Parking meter systems are known in the art. Such parking meter systems generally use cellular telephones or other devices to allow a user to pay for parking, and may also alert the user when additional funds are required to pay for an additional parking interval. Nevertheless, if the meter expires and the vehicle is still parked, parking enforcement personnel must be present to place a ticket on the vehicle for a parking violation. Likewise, if the vehicle leaves the parking space and a new vehicle parks in the meter while time is still present on the meter, then the new vehicle occupant gets a “free ride” on the parking toll paid by the previous user. Thus, prior art systems require significant enforcement resources and also result in lost potential revenue.